added lua regular expression support for Lua.doc.<scope>Name

[NeOzay]

hi,
this PR add support for lua regular expressions for parameters:

• Lua.doc.privateName
• Lua.doc.packageName
• Lua.doc.protectedName

it also adds a new Lua.doc.regengine (the name can be changed) parameter, which can be set to glob(default) or lua

{
  "Lua.doc.protectedName": [
	  "^_[%w_]*_$"
  ],
  "Lua.doc.privateName": [
	  "^_[%w_]*%w$"
  ],
  "Lua.doc.regengine": "lua",
}

---@class A
local A = {}
A._id_ = 0 --  is protected
A._user = "bob" -- is private

---@type A
local t
print(t._id_) -- warning
print(t._user) -- warning

---@class B: A
local t2
print(t2._id_) 
print(t2._user) -- warning

[tomlau10]

I don't think there is a need to add support for lua regex for Lua.doc.<scope> 😕
Currently it is using a custom syntax defined by LPeg.
Though I am not familiar with it, with a bit of testing, your proposed examples can be expressed by:

{
    "doc.protectedName": [
        "_*[a-zA-Z0-9]*_"   // prefix with at least 1 _, contains at least 1 char, then end with _
    ],
    "doc.privateName": [
        "_*",   // prefix with at least 1 _, followed by anything
        "!*_"   // but must not end with _
    ]
}

• In this custom syntax, * just means any number of characters, it DOES NOT mean repeat any times.
• When the 1st character is !, this is a negative pattern.
  And the glob matcher will first check for any negative => return false
  https://github.com/LuaLS/lua-language-server/blame/master/script/glob/glob.lua#L84-L100

---@class A
local A = {}
A._id_ = 0      -- protected
A._id_2_ = 0    -- protected
A.__a_ = 0      -- protected
A._user = "bob" -- private
A._id_3 = 1     -- private
A.__b = 0       -- private
A.test = 1      -- normal
A._ = 1         -- normal
A.__ = 1        -- normal

---@type A
local t = {}
print(t._id_)   -- warning protected
print(t._id_2_) -- warning protected
print(t.__a_)   -- warning protected
print(t._user)  -- warning private
print(t._id_3)  -- warning private
print(t.__b)    -- warning private
print(t.test)   -- ok
print(t._)      -- ok
print(t.__)     -- ok

---@class B: A
local t2 = {}
print(t2._id_)  -- ok
print(t2._id_2_)-- ok
print(t2.__a_)  -- ok
print(t2._user) -- warning private
print(t2._id_3) -- warning private
print(t.__b)    -- warning private
print(t2.test)  -- ok
print(t2._)     -- ok
print(t2.__)    -- ok

---

I found that you have asked this question before in #2324, but seems that the reply doesn't actually answer your question directly 😂

[tomlau10]

(off topic)
I just found a bug (?) related to the glob pattern for single range char set matching.
eg _[a-z] works but _[aeiou] is not working 😕
I have opened an issue #2754 for that.

---

edit: With more testing of the custom built-in glob pattern, its function seems to be somewhat limited and buggy 😕
So this justifies the need of a lua regular expression support 👍

[tomlau10]

I think this function should be declared in the outer scope. Otherwise each call to getVisibleType() will create an unnecessary closure function object, and adds burden to garbage collection.

Maybe something like this:

• outer scope

local function globMatch(patterns, fieldName)
    return glob.glob(patterns)(fieldName)
end

local function luaMatch(patterns, fieldName)
    for i = 1, #patterns do
        if string.find(fieldName, patterns[i]) then
            return true
        end
    end
    return false
end

• here

        local regengine = config.get(uri, 'Lua.doc.regengine')
        local match = regengine  == "glob" and globMatch or luaMatch
        ...
        if #privateNames > 0 and match(privateNames, fieldName) then

[NeOzay]

thanks for the advice. :)

[sumneko]

Thank you!